1. Field of the Invention
The present invention relates to a circuit breaker and, more particularly, to a circuit breaker which is simple in structure and easy to be assembled.
2. Description of Related Art
There are various types of circuit breakers. As shown in FIG. 4, one of them includes a hollow body (40) having an open top and a closed bottom, with the closed bottom defining three slots (41, 42, 43) through which a grounding prong (44), an output blade (45) and an input blade (46) extend downward out of the hollow body (40), respectively.
As clearly shown, the output blade (45) has a bent inner end provided with a first contact (451), while the input blade (46) has a bent inner end formed with a laterally extending bimetallic strip (48) that is provided with a second contact (481) normally engaged with the first contact (451) of the output blade. (45).
At the open top of the hollow body (40), there is a button (50) pivotal about an axle (51). The button (50) is formed with a pair of opposed sidewalls (52), one behind another, and with a leg (60) having a pair of opposed upper lugs (62) situated between and pivotally connected to the sidewalls (52) by a pintle (53). Also pivotally connected to the sidewalls (52) by the same pintle (53) is a hook (65) that has a lower arm beneath the bimetallic strip (48).
The leg (60) further has a boss (61) slidable into a semi-circular recess (49) defined in an inner wall of the hollow body (40), and a first protrusion (601) opposed to the boss (61). The hollow body (40) defines therein a compartment (491) for receiving a holder (64) that has a second protrusion (641) opposite to the first protrusion (601) of the leg (60).
It is between the protrusions (601, 641) that a spring (63) is compressed so as to press the boss (61) of the pivotal leg (60) against the inner wall of the body (40).
Referring to FIG. 5, the bimetallic strip (48) becomes hot and curved upward if an electric overcurrent goes through it as well as the blades (45, 46). The bimetallic strip (48) now pushes the leg (60) upward and hence turns the button (50) in a clockwise direction until the boss (61) of the pivotal leg (60) slides into the semi-circular recess (49) of the body (40) by the action of the compressed spring (63).
From then on, the bimetallic strip (48) is retained in this position by the lower arm of the hook (65) and the contacts (481, 45) are disengaged from each other, unless the button (50) is manually turned counterclockwise again.
It is apparent that this conventional circuit breaker is excessively complex in its structure as it has so many parts to be fabricated.
Furthermore, the hollow body (40) is designed to be covered with a front cover (not shown), which is riveted to the body (40) at several sleeves (47) of the body (40). The manual riveting makes the circuit breaker difficult to be assembled.
Therefore, it is an objective of the invention to provide a circuit breaker to mitigate and/or obviate the aforementioned problems.
The object of the present invention is to provide a circuit breaker which is simple in structure.
Another object of the present invention is to provide a circuit breaker which is easy to be assembled.